Nintendo DS Rumble Pak revealed

Users simply slot the Pak into their GBA slot on the DS, where normally there would be a "Start GBA Game" option. This is replaced by "DS Option Pak Installed." So far Metroid Prime is the only game supporting the Rumble Pak, as games will obviously have to be made with force feedback in mind.

Users have reported that the Rumble Pak is phenomenally loud, unlike those previously made by Nintendo. It has even been suggested that, when active, it produces a loud metallic "chirp" rather than the more normal bearable hum caused by devices like it. More details on the pak can be found here.

According to a user of IGN's forums who claims to be a developer on the upcoming DS FPS Metroid Prime: Hunters, this game too will feature Rumble Pak compatability. The upcoming Mario and Luigi: Partners in Time has also been rumoured the support the Pak, so it appears it won't only games from Metroid publisher Samus that supprt the pack.

More here. µ